Aiming: Why we miss

So, you've aimed the object ball into the pocket you intend to make it in and established center point on the other side of the ball that you need to hit in order to make the ball go in the pocket. The trouble is, you aim at that spot and for some reason miss! Why??? The answer is pretty simple. The point you have visually put all of your focus on is in-fact the "point of contact" which is not the same as where you should be aiming. If you ended up under-cutting the ball, this is probably what happened. In the above diagram, the cue ball was aimed at the point of contact and not the point of aim. As a result, the cue ball actually ends up making contact with the object ball earlier than expected because of the spherical nature of the two balls. Since the cue-ball ends up contacting the object ball earlier than expected, the line drawn from the two centers indicates that the object ball will in-fact miss the side pocket to the far side of the pocket. We call this an "undercut". Undercuts are the most common aiming error made in pool, so don't feel bad if you have been making this mistake. Okay, now that we understand the problem, lets examine how we can fix it. The correct way to aim this shot would be to aim the center of the cue ball to the center of the "Ghost Ball". In pool, the "Ghost Ball" is referred to when an imaginary ball is used as an aiming tool in determining where to drive the cue-ball in a given shot. This imaginary ball represents where the cue-ball would be at the exact moment of impact in order for the object ball to travel in a particular direction. When two balls are touching, the centers of these two balls form a line that show what direction the object ball will travel. If you shoot the ball using the ghost ball aiming point instead of the point of contact, your shot should look like this.